A catch-22: commercial fishing and the evolution of fish

Evolving catches can help or hurt bottom line, depending on how fishing is done.

Few things illustrate the concept of sustainability as clearly as overfishing. When fish are harvested from an area more quickly than they reproduce, the population necessarily shrinks, and the catch shrinks along with it.

But fish may actually be evolving in response to the pressure of fishing, reaching reproductive maturity more quickly. That adaptation comes at a cost, however. Fish that spawn earlier might be less fertile, grow less after they’ve reached sexual maturity, and could become more susceptible to other non-human causes of death. Previous studies have shown that those trade-offs could exacerbate the economic and ecological problem of collapsing fisheries.

A new study this week suggests that these genetic changes could actually be economically beneficial to fisheries—but only if they’re managed sustainably.

The researchers built a computer model that simulated both the fish population and the economics of the fishing industry, using the Atlantic cod fishery of Russia and Norway as an example. While it used to be much healthier, this fishery still yields a billion US dollars or so of fish each year.

The team first explored simulations where the catch was managed at a sustainable level. In one version, the model allowed the simulated fish to evolve in response to fishing pressures. In the other, genes were frozen. In the evolutionary simulation, the catch actually became a little greater over time as the genetics of the population changed. In this scenario, adaptation is an economic boon.

Unfortunately, the fish are not being harvested sustainably. So the researchers ran the same experiment using historic harvest figures. Here the result was different—the evolutionary simulation showed a slightly smaller catch over time compared with the “frozen genes” version.

How could this genetic adaptation be beneficial in one scenario but detrimental in another? It has to do with the minimum size of fish that are caught. If you only catch large fish, the population won’t evolve much because fish can easily reproduce before being caught. If you catch even the small fish, the advantage of genetic adaptation is quite large. Very few late-maturing fish will reproduce before being caught, but in the middle, things get a little weird.

If the fish grow faster, that means they also reach catchable size at a younger age. At this intermediate minimum catch size, too many fish are caught before reproducing. Pressure to reach a reproductive size earlier makes fish bigger, and being bigger gets fish caught—it’s a fish catch-22. Greater evolutionary pressure (in the form of catching even the smaller fish) can push maturity early enough to move into the win column, but in the intermediate case it’s a net loss.

If fish are harvested sustainably, evolution doesn’t need to be taken into account. But where overfishing is still taking place, the wrong minimum catch size can exacerbate the problem. “Admittedly, those evolutionary costs are small,” the researchers write, “but they may just be enough to push a fish stock from the state of overexploitation into collapse.”

The study also notes another ramification: the genetic changes could skew the data used to monitor fisheries. The number of sexually mature fish is commonly used as an indicator of the total population. In an evolving population, a greater proportion is sexually mature—so counts of mature fish could hold steady even as the total population drops.

39 Reader Comments

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

While so far large societies have never really gotten sustainable practices right, marine fish harvesting is one of the easier places to remedy that. Population declines in marine species are generally the result of overharvest, where as terrestrial and aquatic species tend to have population declines due to habitat destruction/degradation. This means that unlike terrestrial and aquatic species that require intensive habitat repair to increase populations, marine species just need to left alone in order to recover since most of their habitat is still available. I understand that not catching highly valuable commercial species is a problem in its own right, but it certainly isn't an unattainable goal.

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

You know species were going extinct like crazy when our population was less than half it was today? Cutting the population by 50% won't help a damn if we don't change how we live. And looking at the birth rates in affluent countries, then it seems the population issue takes care of itself once your standard of living reaches a certain point. The key is finding a way to do that sustainably, and for as much of the world as possible. Hardly a simple task. Except compared to keeping as much of the world as possible from making babies in some other fashion.

Simpler said than done. Cut the population growth by 50-80%? China and India beg otherwise even with exploding populations even with restrictions on reproduction.

Cutting our environmental impact is ideal but there are too many people who just don't care. This is one of those problems that "the next generation" will have to solve just like every previous generation has said.

It's not a catch-22 at all... Humans set a minimum size limit on fish catches, and we were just simply completely WRONG. Drop that rule, and everything will work out far better than the mess we have now (fish evolving to be smaller adults). There is no paradox here.

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So it's easier to stop humans from making babies than fishing? Is this a joke from the fifties that I don't get?

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

Increasing human populations aren't the problem, and reducing human populations won't solve the problem. Increasing consumption of scarce resources is caused by increasing prosperity. The growth of Japan's economy was a hard hit for tuna, for example, and many other species.

So what you really want to say is that, if we just made the world poorer, this problem would solve itself. Good luck pitching that one...

The "overpopulation" scare tactic is much more popular, and has been a mainstay of alarmist fools and charlatans for CENTURIES:

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

If you're implying that our ability to drive species to extinction is inherent from our population, you're wrong. We've been extincting species for hundreds (probably thousands) of years. Think of the American bison- it was driven near extinction long before present population levels. If going back to a nascent-Industrial-era population level is what you had in mind, it ain't gonna happen.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

Increasing human populations aren't the problem, and reducing human populations won't solve the problem. Increasing consumption of scarce resources is caused by increasing prosperity. The growth of Japan's economy was a hard hit for tuna, for example, and many other species.

So what you really want to say is that, if we just made the world poorer, this problem would solve itself. Good luck pitching that one...

The "overpopulation" scare tactic is much more popular, and has been a mainstay of alarmist fools and charlatans for CENTURIES:

It is totally a Catch-22... unless we change the rules based on realizing that's what it is.

It's just one rule that worked out badly, so we need to change it. That happens all the time. Where is the logical conundrum? Where is the paradox? Where is it that all possibilities are bad or wrong?

For the fish. If they don't evolve, they get captured too much before reproducing and the population crashes. If they do evolve, then it just changes what fish get captured to include the ones that evolved to mature earlier and the population still crashes. Damned if they do, damned if they don't.

If we change the rules, then we can break the fish catch-22.

JUST LIKE if the bureaucrat who invented rule Catch-22 -- as in the actual Catch-22 from the book Catch-22 that coined the term Catch-22 -- had declared Catch-22 invalid, then it wouldn't have been a Catch-22 anymore.

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

You know species were going extinct like crazy when our population was less than half it was today? Cutting the population by 50% won't help a damn if we don't change how we live. And looking at the birth rates in affluent countries, then it seems the population issue takes care of itself once your standard of living reaches a certain point. The key is finding a way to do that sustainably, and for as much of the world as possible. Hardly a simple task. Except compared to keeping as much of the world as possible from making babies in some other fashion.

Well, we could always just power up Sky Net and let the machines save the fish in their own way...

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

Increasing human populations aren't the problem, and reducing human populations won't solve the problem. Increasing consumption of scarce resources is caused by increasing prosperity. The growth of Japan's economy was a hard hit for tuna, for example, and many other species.

So what you really want to say is that, if we just made the world poorer, this problem would solve itself. Good luck pitching that one...

The "overpopulation" scare tactic is much more popular, and has been a mainstay of alarmist fools and charlatans for CENTURIES:

Any attempt to deny this is based wholly around willfully ignoring resource constraints. Contrary to points made on that page, physical space is not the limiting factor (much as atmospheric CO2 is not a limiting factor in plant productivity).

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

You know species were going extinct like crazy when our population was less than half it was today? Cutting the population by 50% won't help a damn if we don't change how we live. And looking at the birth rates in affluent countries, then it seems the population issue takes care of itself once your standard of living reaches a certain point. The key is finding a way to do that sustainably, and for as much of the world as possible. Hardly a simple task. Except compared to keeping as much of the world as possible from making babies in some other fashion.

He does have a point. Let's look at it this way: you are a poor fisherman in a less-developed nation. You must fish to survive. Your government puts out new guidelines that make 50% of your catch unfishable now under the auspices of keeping the fishing sustainable. You know your family will starve on only half-catches now, and you can't wait for populations to catch up in a few years due to this new initiative. What are you going to do? you're going to fish illegally and keep your family alive. The abstract morality of sustainable fishing is well beyond the concept of anyone who is dealing with the immediate morality of keeping their family alive.

As long as we have more people than our environment can support, the concept of sustainability means little. (note, I don't know if we truly have more than we can support, this was simply a thought exercise)

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

You know species were going extinct like crazy when our population was less than half it was today? Cutting the population by 50% won't help a damn if we don't change how we live. And looking at the birth rates in affluent countries, then it seems the population issue takes care of itself once your standard of living reaches a certain point. The key is finding a way to do that sustainably, and for as much of the world as possible. Hardly a simple task. Except compared to keeping as much of the world as possible from making babies in some other fashion.

He does have a point. Let's look at it this way: you are a poor fisherman in a less-developed nation. You must fish to survive. Your government puts out new guidelines that make 50% of your catch unfishable now under the auspices of keeping the fishing sustainable. You know your family will starve on only half-catches now, and you can't wait for populations to catch up in a few years due to this new initiative. What are you going to do? you're going to fish illegally and keep your family alive. The abstract morality of sustainable fishing is well beyond the concept of anyone who is dealing with the immediate morality of keeping their family alive.

As long as we have more people than our environment can support, the concept of sustainability means little. (note, I don't know if we truly have more than we can support, this was simply a thought exercise)

While it's great that you've got a narrative with "poor fisherman", but you ought to realise that most of the world's fish are caught by fishing companies looking to turn a higher profit. http://en.wikipedia.org/wiki/Commercial_fishing

He does have a point. Let's look at it this way: you are a poor fisherman in a less-developed nation. You must fish to survive. Your government puts out new guidelines that make 50% of your catch unfishable now under the auspices of keeping the fishing sustainable. You know your family will starve on only half-catches now, and you can't wait for populations to catch up in a few years due to this new initiative. What are you going to do? you're going to fish illegally and keep your family alive. The abstract morality of sustainable fishing is well beyond the concept of anyone who is dealing with the immediate morality of keeping their family alive.

Now think about what happens if the government says you can only have one child per couple. The poor fisherman, who doesn't have access to birth control, and also needs to have children to help with the catch and then some as a hedge for those who are going to die young.

Which rule is more likely to be obeyed?

My bet is not the one that requires this fisherman to stop having sex.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

Increasing human populations aren't the problem, and reducing human populations won't solve the problem. Increasing consumption of scarce resources is caused by increasing prosperity. The growth of Japan's economy was a hard hit for tuna, for example, and many other species.

So what you really want to say is that, if we just made the world poorer, this problem would solve itself. Good luck pitching that one...

The "overpopulation" scare tactic is much more popular, and has been a mainstay of alarmist fools and charlatans for CENTURIES:

Yeah that link was biased and sensationalist. It's like sending someone to Fox News for fair and balanced reporting. The 1960's population control movement was fueled by the baby boom. I believe in perfect storm historical events, where multiple elements come together at a time when they have to. And in this case it was the birth control pill that was introduced in 1960 that directly correlates with the end of the baby boom. Not only that but culturally people were looking to have less children. Prior to WW2 higher populations were necessary because of higher mortality and the need for hands to work on the farm. Today people are living longer, infant mortality is reduced and there is no farm. Having more children is actually a financial strain as it cost approx $120,000 to $220,000 to raise a child to the age of 18 and that is part of the perfect storm that is causing birth rates to decline today.

Choosing not to have children today will leave you better off financially. And as for the whole "everyone in the world could live on a square in Texas" thing … yeah, you can cancel my subscription to Earth if it ever gets to that point.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

Actually, it's trivial to do so with market forces, as the sea-change in the reproductive patterns of developed nations shows. It's not just that we have more stuff to do in the developed world than just have sex--it's that these things, and desires to get more of them, become incentives to not reproduce as much. If you offer more resources and a more comfortable lifestyle to people who delay reproduction and/or reproduce less, a large number will choose (not necessarily consciously) to do so in order to have those greater resources and more comfortable lifestyles. That's one of the forces which causes birth rates to fall in developed countries--let's call it "the carrot." There's another side to this same market-driven change in reproductive rates--let's call it "the stick"--in that people in developed countries, once exposed to the resources and comfort afforded by "the carrot," will place themselves on time-consuming and demanding career paths to obtain more of them, thereby further de-prioritizing reproductive desires and decreasing reproductive opportunities. It becomes a self-sustaining feedback loop.

The problem is, we completely eliminate the action of these market forces with conventional wealth redistribution schemes, whereas well-crafted wealth redistribution schemes would use them to advantage. When we give flat support payments (in developed nations) or material food resources (in developing ones) to the poor, we encourage the poor to reproduce more frequently than the well-off--leading to an imbalance which increases geometrically generation after generation, and a cycle of increasing dependence. This is one of the reasons (though there are many other structural/institutional ones) why the developed nations have been supporting Africa extensively since the 1950s through direct food aid as well as economic transfer payments, but Africa's number of poor has continued to increase even as aid has increased (200 million in poverty circa 1980, over 350 million in poverty today). Sadly, our humanitarian impulses can lead to greater and greater suffering--preventing deaths from starvation in one generation, with no inducements to population control, leads to far greater numbers of deaths from starvation compounded across future generations.

A well-crafted wealth redistribution scheme to aid the poor would allow market forces to encourage people to have fewer children in exchange for greater resources and a more comfortable lifestyle, just as they do among those with more resources in the developed world. It would have to look a little different in the developed world than in the developing one, though. In the developed world, there are good reasons why we should craft welfare systems to encourage lower birth rates among the poor, but there are those who argue that we need more workers than we have (for reasons ranging from sustaining general economic growth to the graying of the workforce and the need to have more workers to support increasing numbers of retired people, etc.) so rather than go off on a tangent about that (misguided and short-sighted) argument I'll just address what such a program could look like in the developing world.

Instead of giving away food aid or monetary welfare flatly, the amount of disbursements should be structured to favor those who have fewer children. Right now one of the reasons poor women in Africa have so many children is that a woman's children are her retirement program--each child she has is likely to contribute a small portion of his or her income to supporting her, which encourages her to have more. High mortality rates for these children perpetuate suffering, and those who do live to reproduce themselves contribute geometrically to the overall problem. So government aid should counteract this--the more children you've had, the less government aid disbursement you receive. But, it can be structured as a system of "carrots" rather than one of "sticks"--young females of childbearing age should be given a "bonus" disbursement for not having children, thus discouraging early childbirth. In those cultures where it's a problem, this could also discourage early and forced marriage, and discourage sex-selective abortion of female fetuses--if an unmarried girl with no children is a potential source of bonus support for the family, that could even lead to sex-selective abortion of male fetuses (which could be a net positive for these cultures over time, for various reasons we can argue about later).

But anyway, I digress. The point is that it's certainly possible to engineer human reproductive rates by incentivizing them--which is basically what we've done unintentionally in the developed world--and that most of our pressing environmental problems (whether overfishing, pollution, global warming via GHGs, whatever) would be far less pressing if the human population were decreased through such incentives. We need to think like engineers and create systems which work better, not just throw up random patches wherever we see problems.

He does have a point. Let's look at it this way: you are a poor fisherman in a less-developed nation. You must fish to survive. Your government puts out new guidelines that make 50% of your catch unfishable now under the auspices of keeping the fishing sustainable. You know your family will starve on only half-catches now, and you can't wait for populations to catch up in a few years due to this new initiative. What are you going to do? you're going to fish illegally and keep your family alive. The abstract morality of sustainable fishing is well beyond the concept of anyone who is dealing with the immediate morality of keeping their family alive.

Now think about what happens if the government says you can only have one child per couple. The poor fisherman, who doesn't have access to birth control, and also needs to have children to help with the catch and then some as a hedge for those who are going to die young.

Which rule is more likely to be obeyed?

My bet is not the one that requires this fisherman to stop having sex.

Funny thing is, adding free/easy access to birth control in developing nations actually helps this a lot (well, along with education on proper use). In those situations, people as population groups tend to manage to the number of children they can handle, or want to handle. This makes for much slower population growth without any aggressive regime.

So, we are basically forcing fish to all evolve into sardines. In the short term, faster maturation would win out, but in the long term, actual downsizing is more likely. Fortunately, I like sardines, and faster maturing fish accumulate fewer toxins, so they are better for you. But still, I'm a bit conflicted about a future with only small fish. Unfortunately it's pretty inevitable in a world where the seas are a "commons" and fishermen act like, well, fishermen always have: catch what you can, no matter what, and blame everyone but themselves when the fisheries collapse.

He does have a point. Let's look at it this way: you are a poor fisherman in a less-developed nation. You must fish to survive. Your government puts out new guidelines that make 50% of your catch unfishable now under the auspices of keeping the fishing sustainable. You know your family will starve on only half-catches now, and you can't wait for populations to catch up in a few years due to this new initiative. What are you going to do? you're going to fish illegally and keep your family alive. The abstract morality of sustainable fishing is well beyond the concept of anyone who is dealing with the immediate morality of keeping their family alive.

Now think about what happens if the government says you can only have one child per couple. The poor fisherman, who doesn't have access to birth control, and also needs to have children to help with the catch and then some as a hedge for those who are going to die young.

Which rule is more likely to be obeyed?

My bet is not the one that requires this fisherman to stop having sex.

The poor fisherman needs to have more children to help catch the fish that aren't enough to feed his family. That sounds like a losing business model ... get that man (or his lady) some birth control ASAP!

In all seriousness mankind has a tendency to exhaust all resources in an area until it is barren causing mass suffering and mortality then after moving on or rectifying the situation set it up so the whole thing happens all over again. It's just like Wall Street, we inflate our bubbles till they burst. The dust bowl was 100% man-made, and without government intervention it would have been a lot worse. The farmers had land they invested in for farming which was no longer farmable, but for them the land needed to be farmed, so they kept trying to farm unfarmable land. The only way to fix the situation was to pay farmer not to grow anything and to teach them sustainable farming practices.

It's the same with the fish. We can either throttle down the fish tap and retain a consistent supply of fish so that fish population and consumption remain in harmony ... or we could just go all Wall Street on their asses and open the fish tap all the way and have 10 years of lucrative fishing followed by 50 years of sparse amounts of tiny fish.

Goal seeking evolution, not sure what text book I have to read to know about this science :-)

For those wondering what I mean: fish are not targeting a particular goal (i.e. trying to reproduce under (over)fishing). What actually happens is natural selection (there is no evolving here going on). I.e. we have fish with slightly different genes, some genes reproduce early, some late.

If you catch only mature fish, or only those over a certain size, fishers are removing the slow producing genes from the gene pool. So only the quick maturing are left.

And I can assure you the quick maturing genes are very unlikely ever to evolve to slow maturing. It's simply genetic material that's lost. And forever lost if these fish are unique to a region.

Disappointing to see this weird description of what's actually going on Scott.

It is totally a Catch-22... unless we change the rules based on realizing that's what it is.

It's just one rule that worked out badly, so we need to change it. That happens all the time. Where is the logical conundrum? Where is the paradox? Where is it that all possibilities are bad or wrong?

For the fish. If they don't evolve, they get captured too much before reproducing and the population crashes. If they do evolve, then it just changes what fish get captured to include the ones that evolved to mature earlier and the population still crashes. Damned if they do, damned if they don't.

If we change the rules, then we can break the fish catch-22.

JUST LIKE if the bureaucrat who invented rule Catch-22 -- as in the actual Catch-22 from the book Catch-22 that coined the term Catch-22 -- had declared Catch-22 invalid, then it wouldn't have been a Catch-22 anymore.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

Actually, it's trivial to do so with market forces, as the sea-change in the reproductive patterns of developed nations shows. It's not just that we have more stuff to do in the developed world than just have sex--it's that these things, and desires to get more of them, become incentives to not reproduce as much. If you offer more resources and a more comfortable lifestyle to people who delay reproduction and/or reproduce less, a large number will choose (not necessarily consciously) to do so in order to have those greater resources and more comfortable lifestyles. That's one of the forces which causes birth rates to fall in developed countries--let's call it "the carrot." There's another side to this same market-driven change in reproductive rates--let's call it "the stick"--in that people in developed countries, once exposed to the resources and comfort afforded by "the carrot," will place themselves on time-consuming and demanding career paths to obtain more of them, thereby further de-prioritizing reproductive desires and decreasing reproductive opportunities. It becomes a self-sustaining feedback loop.

The problem is, we completely eliminate the action of these market forces with conventional wealth redistribution schemes, whereas well-crafted wealth redistribution schemes would use them to advantage. When we give flat support payments (in developed nations) or material food resources (in developing ones) to the poor, we encourage the poor to reproduce more frequently than the well-off--leading to an imbalance which increases geometrically generation after generation, and a cycle of increasing dependence. This is one of the reasons (though there are many other structural/institutional ones) why the developed nations have been supporting Africa extensively since the 1950s through direct food aid as well as economic transfer payments, but Africa's number of poor has continued to increase even as aid has increased (200 million in poverty circa 1980, over 350 million in poverty today). Sadly, our humanitarian impulses can lead to greater and greater suffering--preventing deaths from starvation in one generation, with no inducements to population control, leads to far greater numbers of deaths from starvation compounded across future generations.

A well-crafted wealth redistribution scheme to aid the poor would allow market forces to encourage people to have fewer children in exchange for greater resources and a more comfortable lifestyle, just as they do among those with more resources in the developed world. It would have to look a little different in the developed world than in the developing one, though. In the developed world, there are good reasons why we should craft welfare systems to encourage lower birth rates among the poor, but there are those who argue that we need more workers than we have (for reasons ranging from sustaining general economic growth to the graying of the workforce and the need to have more workers to support increasing numbers of retired people, etc.) so rather than go off on a tangent about that (misguided and short-sighted) argument I'll just address what such a program could look like in the developing world.

Instead of giving away food aid or monetary welfare flatly, the amount of disbursements should be structured to favor those who have fewer children. Right now one of the reasons poor women in Africa have so many children is that a woman's children are her retirement program--each child she has is likely to contribute a small portion of his or her income to supporting her, which encourages her to have more. High mortality rates for these children perpetuate suffering, and those who do live to reproduce themselves contribute geometrically to the overall problem. So government aid should counteract this--the more children you've had, the less government aid disbursement you receive. But, it can be structured as a system of "carrots" rather than one of "sticks"--young females of childbearing age should be given a "bonus" disbursement for not having children, thus discouraging early childbirth. In those cultures where it's a problem, this could also discourage early and forced marriage, and discourage sex-selective abortion of female fetuses--if an unmarried girl with no children is a potential source of bonus support for the family, that could even lead to sex-selective abortion of male fetuses (which could be a net positive for these cultures over time, for various reasons we can argue about later).

But anyway, I digress. The point is that it's certainly possible to engineer human reproductive rates by incentivizing them--which is basically what we've done unintentionally in the developed world--and that most of our pressing environmental problems (whether overfishing, pollution, global warming via GHGs, whatever) would be far less pressing if the human population were decreased through such incentives. We need to think like engineers and create systems which work better, not just throw up random patches wherever we see problems.

Yes something along the lines of "I'll pay for your current children to recieve an education if you agree to come in every 3 months for a Nortrel injection."

Goal seeking evolution, not sure what text book I have to read to know about this science :-)

For those wondering what I mean: fish are not targeting a particular goal (i.e. trying to reproduce under (over)fishing). What actually happens is natural selection (there is no evolving here going on). I.e. we have fish with slightly different genes, some genes reproduce early, some late.

If you catch only mature fish, or only those over a certain size, fishers are removing the slow producing genes from the gene pool. So only the quick maturing are left.

And I can assure you the quick maturing genes are very unlikely ever to evolve to slow maturing. It's simply genetic material that's lost. And forever lost if these fish are unique to a region.

Disappointing to see this weird description of what's actually going on Scott.

This guy called Charles Darwin -- I suspect you've heard of him -- became one of the most famous people in the entire world and in modern history, by figuring out an actual mechanism by which evolution could and does occur.

What actually happens is natural selection (there is no evolving here going on). I.e. we have fish with slightly different genes, some genes reproduce early, some late.If you catch only mature fish, or only those over a certain size, fishers are removing the slow producing genes from the gene pool. So only the quick maturing are left.And I can assure you the quick maturing genes are very unlikely ever to evolve to slow maturing. It's simply genetic material that's lost. And forever lost if these fish are unique to a region.Disappointing to see this weird description of what's actually going on Scott.

Yes something along the lines of "I'll pay for your current children to recieve an education if you agree to come in every 3 months for a Nortrel injection."

We can structure it as a positive incentive, not as a direct payment, such that it's not potentially morally objectionable. In the developed world, it could be a reform of children's welfare support something more like "All children whose parents don't attain X level of income, beginning at age 13, will receive an additional monthly disbursement for their support. That disbursement will increase yearly at Y schedule, until age Z [sometime in their 20s], or until their parents (or they themselves if over 18) reach X level of income. This disbursement will be reduced by A% if the recipient has a child, and B% for each additional child, to defray the State's cost of support for those children." All perfectly reasonable, and structured as a positive bonus above what that person would otherwise receive, rather than a negative penalty. The variables would be adjusted according to research and projections regarding what would be most effective, of course.

I don't see what's objectionable about such a proposal. If you do, please enlighten me.

As well as changes to reach maturity earlier, is there an evolutionary pressure towards foul-tasting fish with lots of bones so that we wouldn't want to eat them? and how long has that sort of thing taken to happen in species that feature it as a defence against being eaten?

As well as changes to reach maturity earlier, is there an evolutionary pressure towards foul-tasting fish with lots of bones so that we wouldn't want to eat them?

Foul tasting would do it where man is concerned, lots of bones would not. Case in point, no one eats flying fish, they do taste bad. Whereas the fish I know by the name 'milkfish' tastes great, but has so many bones that one must eat it with care, and it's not appropriate for small children..

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and how long has that sort of thing taken to happen in species that feature it as a defence against being eaten?

I agree, that would be a better defense, at least where man is concerned. I'm not so sure about nature though. Case in point is the golden poisonous frog.

-- The golden poison frog, like most other poisonous frogs, stores its poison in skin glands. Due-- to their poison, the frogs taste vile to predators; P. terribilis poison kills whatever eats it, except-- for one snake species, Liophis epinephelus. This snake is resistant to the frog's poison, but is -- not completely immune.

It seems the snake evolved along with it's prey. But my point is, tasting bad may not protect you from natural predators, although I think being poisonous is an even better (but still imperfect) approach.

is there an evolutionary pressure towards foul-tasting fish with lots of bones so that we wouldn't want to eat them?

Extremely unlikely. Even if there was a bony or bad-tasting fish among shoals of fish, they'd still get caught in the same nets, and die aboard fishing vessels. They'd get thrown-out rather than sold to consumers, but they'd still be dead, unable to reproduce and spread their mutations, and therefore no evolution.

They need some mutation that helps them avoid being captured and killed in the first place. Being smaller is one of those. Maybe some bony outcropping that was strong and sharp enough to cut through fishing nets would turn up eventually, but fishermen would quickly switch to using stronger net materials.

is there an evolutionary pressure towards foul-tasting fish with lots of bones so that we wouldn't want to eat them?

Extremely unlikely. Even if there was a bony or bad-tasting fish among shoals of fish, they'd still get caught in the same nets, and die aboard fishing vessels. They'd get thrown-out rather than sold to consumers, but they'd still be dead, unable to reproduce and spread their mutations, and therefore no evolution.

They need some mutation that helps them avoid being captured and killed in the first place. Being smaller is one of those. Maybe some bony outcropping that was strong and sharp enough to cut through fishing nets would turn up eventually, but fishermen would quickly switch to using stronger net materials.

So perhaps any evolutionary pressure would be on us humans, to like the taste / digest the food source better? ... :-)

We got it backwards. The challenge is not to maintain sustainable levels of fish. That has never worked and will never work; think of all the thousands of species that are going extinct due to human encroachment, polluting, poaching or simply not giving a damn.

The real challenge is to rewire our insatiable drive to procreate. If we could reduce our environmental footprint by 50%-80%, nature would have time to replenish the species we are devouring.

So you think that getting people to give a damn about the environment and use sustainable practices has never and will never work.

But getting people to ignore their reproductive drive -- the most fundamental instinct of any sexually reproducing animal, arguably even more so than the survival instinct -- is totally plausible?

Oookay.

@wyrmhole and you say that when people like Octo-mom and families that have 10-20 children are running around procreating - constantly adding to the over-population of humans. I won't even get into the impoverished side of society runinng around with ±9 kids recurringly. basically folks getting pregnant every time they have sex. This coming froma species that is supposed to have a higher ability for thought over other animals ? Why do these people need 15 kids ?

7+ billion people on the planet and you really think we're NOT over-populated ? How many people is too many for the planet ? 10 Billion - 100 Billion - no limit ?

It's not like we're a colony of ants who each take up less than a quarter inch of space. So several billion ants won't amount to much more than a few square miles.

Now I do disagree with a blanket wiping of 80% of the human population overnioght simply to accommodate over-crowding and more food for everyone.

At the same time - there are mass amounts of food in general that go to waste that never get to starving folks (which is a topic for a different article).